Umami is hardly a foreign concept in Japan. After all, this is the land where the so-called fifth taste was isolated, named and promptly marketed to the outside world.

Now, it's come full circle: Umami Burger has touched down in Aoyama, bringing the premium product that is the extra-savory signature of this Los Angeles-based chain.

It's a great idea. Instead of boosting the beef patties with artificial additives, more natural, umami-rich ingredients are used, such as soy sauce and porcini mushrooms. The basic eponymous burger is served with shiitake, roast tomato and a crisp disk of Parmesan cheese. That's plenty of taste to tantalize your tongue.

But it's not a fast food joint. Once you've been seated, you're given lots of time to decipher the menu. The K-BBQ burger comes with gochujang (Korean hot sauce) glaze. The Sunny Side Up has truffle oil with its egg. And the Manly Burger? That brings you apple-wood smoked bacon and a lot more. All are prepared to order and cooked just as well or as rare as you choose.

It does have to be said: Umami Burger is not cheap. If you've ordered a craft beer or cocktail, plus some wings, skinny fries and a salad to have while you wait, dinner can easily add up to ¥5,000 a head.

Burgers from ¥1,380 (plus tax); English menu, English spoken.